The present invention relates to a storage management method and a management server technology.
With information technologies spreading in a variety of business fields, the number of physical servers and the volume of data corporations hold have been continuing to rise. Under this circumstance a spotlight is being focused on a server virtualization technology to collectively manage an increasing number of physical servers to reduce their number and on a collective management of storage based on the SAN (Storage Area Network). Behind this trend there is a growing number of corporations intent on solving such problems as an increase in power consumption and exhaust heat volume due to increased densities of physical server groups and storage device groups and a scarcity of available floor space because of an increasing number of physical servers and storage devices.
The server virtualization is a technology that divides one physical server into a plurality of virtual machines (these virtually divided servers are hereinafter called virtual machines) and allocates computer resources such as CPU (Central Processing Unit) and memory of the physical server to individual virtual machines so that they can execute an OS (Operating System) and applications. One such server virtualization technology example is a technology that relocates the virtual machines among different physical servers (see U.S. Pat. No. 6,802,062).
According to the technology disclosed in this patent document, when the computer resources of a physical server allotted to virtual machines run out, it is attempted to search a new physical server able to allocate more computer resources and, if it is found, relocates the virtual machines to this server and allocates them to the server. This server virtualization allows the performance problems to be solved by utilizing the computer resources currently not in use, without having to purchase new physical servers, which in turn leads to a reduction in the total number of physical servers the corporation owns.
Next, a collective management of storage based on SAN will be explained. In an environment with no collective storage management in operation, a dedicated storage device needs to be provided to each server. When each server is provided with a dedicated storage device, unused disks present in the individual storage devices cannot be put to effective use, resulting in the disk volume owned by the company becoming huge. The SAN-based collective management of storage lets a single storage device be shared among a plurality of servers by connecting the servers to the storage device via networks. This enables the unused disks to be shared by a plurality of servers, reducing the number of storage devices and the disk volume owned by the company.
As described above, by combining the server virtualization and the collective storage management based on SAN, the number of physical servers and storage devices that a corporation maintains can be reduced.